The present invention relates to rotors in synchronous machines. In particular, the invention relates to supports for a rotor field winding in generators.
Conventional generators have rotors that support field windings. These rotors typically have rotor cores with axial slots that receive each turn of the field windings. These rotor slots restrain the windings against the centrifugal forces that arise as the rotor spins. During assembly, the winding is installed turn by turn in the slots of the rotor core. The winding is assembled as it is installed in the slots of the rotor core. Assembling the winding as it is installed in the rotor core is inefficient, time consuming and requires highly-skilled technicians. There is a need for an improved method of installing a field winding in the rotor core of a generator.
A modular field winding support system has been developed. This system allows for pre-formed winding turns to be installed in a rotor core. The modular support system includes a series of winding spacers that hold each of the winding turns. These spacers are laterally spaced along the long side of the windings. Each spacer holds a plurality of windings. A group of spacers collectively hold a nested assembly of windings. The winding spacers and hence the windings are secured to a rotor core by a locking mechanism. A rotor core may support a pair of opposite assemblies of windings.
The winding spacers are fitted to the pre-fabricated windings prior to their assembly with the rotor core. The winding spacers have some flexibility to adjust to variances in the winding turns and the rotor core. The pre-fabricated winding turns and winding spacer assembly is mounted on the rotor core. A locking mechanism secures the winding support and the winding turns to the rotor core.
In a first embodiment, the invention is a winding assembly for a rotor comprising: a plurality of rotor field windings, and a winding support holding said winding in a slot of the support, wherein the winding assembly is mountable on said rotor.
In another embodiment, the invention is a winding assembly for a rotor core comprising: an array of field windings arranged in an array, each of said windings having a pair of opposite long sides, and a pair of opposite end sections and a plurality of winding spacers supporting the long sides of said field windings, said winding spacers each having a first edge and a second edge, wherein each of said first edges slidably engage a respective spacer slot on a first surface of the rotor core, and each of said second edges engage a respective spacer slot on a second surface of the rotor core.
In a further embodiment, the invention is a method for assembling a plurality of field windings and securing the windings on a rotor core comprising the steps of: arranging a plurality of field windings in a winding assembly using a plurality of spacers to hold the windings in the assembly, wherein each spacer has a plurality of slots and each slot receives one of said plurality of rotor windings; mounting the winding assembly on the rotor core by inserting edges of the plurality of spacers into slots on the rotor core, and securing the edges of the plurality of spacers to the rotor core.